1. Technical Field
This invention relates to upholstery fabric intended to cover at least part of the surface of a three-dimensional structure. The invention has particular, but not exclusive, reference to upholstery for an automobile seat, or a seat for other vehicles such as trains, aeroplanes, boats, buses, lorries or other modes of transport. As well as upholstered seats in vehicles or other modes of transport the invention may be used in other upholstered structures in vehicles and modes of transport, such as side cushions for protection or decoration. Further additionally the invention may be used in upholstery for non-transport applications such as seats in houses, offices etc, and upholstered structures generally used for appearance or padding or both.
2. Background Art
The usual method of manufacturing a vehicle seat cover involves converting yarn into woven fabric, cutting out shaped pieces of the woven fabric to make the seat back cover and subsequently sewing these pieces together to form the base and back covers. It is also necessary to provide anchorage devices at the edges of the base and back covers to enable attachment of the covers to respective cushions. Usually these anchorage devices take the form of hollow sewn hems which can be secured to metal rods recessed into the cushions. If the base and/or back cushions comprise bolsters, it is also necessary to provide anchorage devices, usually in the form of open looped flaps, on the undersurface of the cover, in order to conform the cover to the shape of the upper surface of the cushion. Apart from being wasteful in fabric, this method of manufacturing vehicle seat covers is extremely time-consuming and is therefore very costly. Additionally, the amount of time taken to design and produce the warps for weaving; weave the fabric; stenter the fabric; design the patterns; cut and sew, means that design changes in woven seat covers can take eighteen months or more to implement.
Recently, it has been found possible to knit one-piece upholstery fabrics which, without the need for sewing portions together, have the desired shapes to serve as covers for the base and back cushions of a vehicle seat, and incorporate the anchorage devices for the tubes. See UK Patent Application No.2,223,034 A.
An aim of the present invention is to provide such a piece of knitted upholstery fabric with a "mechanical structure" further facilitating its retention on a three-dimensional support, such as a vehicle seat cushion.